1) Added new apis: createFirewallRule, deleteFirewallRule, listFirewallRules
2) Modified existing apis - added boolean openFirewall parameter to createPortForwardingRule/createIpForwardingRule/createRemoteAccessVpn. If parameter is set to true, open firewall on the domR before creating an actual PF rule there
Modified backend calls appropriately.
3) Schema changes for firewall_rules table:
* startPort/endPort can be null now
* added icmp_type, icmp_code fields (can be not null only when protocol is icmp)
4) Added new manager - FirewallManagerImpl
Created a table for source cidrs list.
Created necessary Daos and VOs.
Updated PortForwardingRulesDao to persist/update non null list of cidrs.
For deletion depending on ON DELETE CASCADE.